Table 2.

Summary of ACTase activity characteristics in H. pylori

Enzyme characteristic	Data from H. pylori ACTase
Km (carbamoyl phosphate)	0.6 mM
Km (L-aspartate)	11.6 mM
Vmax (carbamoyl phosphate)	0.68 μmole min-1 (mg protein)-1
Vmax (L-aspartate)	0.64 μmole min-1 (mg protein)-1
pH optimum	8.0
Temperature optimum	45°C
Substrate specificity	Specific for L-aspartate
Effect of aspartate analogues	Succinate and malate inhibit
Effect of phosphate analogues	Phosphonoacetate and acetyl phosphate inhibit
Effect of PALA	50% inhibition at 0.1 μM; Ki of 0.245 μM
Effect of nucleotides	All, tri-, di-, and monophosphate nucleotides inhibit